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Finding the Fourth Proportional to 815.77, 1,223.08 and 425.99

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Solution

The fourth proportional to 815.77, 1,223.08 and 425.99 is: 638.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.77 : 1,223.08 = 425.99 : x
  2. Step 2: Convert to fraction form
    815.77/1,223.08 = 425.99/x
  3. Step 3: Cross multiply
    815.77x = 1,223.08 × 425.99
  4. Step 4: Simplify right side
    815.77x = 521,011.60
  5. Step 5: Solve for x
    x = 521,011.60/815.77
  6. Step 6: Final answer
    x = 638.68

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.